This proposal is a collaboration between Rutgers University-Newark (New Jersey, USA) and the Al-Quds University (Abu Dis, West Bank/Palestinian Territories) to support research, education, and infrastructural development for Collaborative Research on Learning and Decision Making in Patients with Major Depressive Disorder. Focusing on Major Depressive Disorder (MDD) targets a critical local mental health issue and provides a rare opportunity to take advantage of the many unique cultural, environmental, familial, and clinical aspects of MDD among West Bank Palestinians with implications for advancing the science and clinical treatment of MDD worldwide. In 2008 the Rutgers/Al-Quds Brain Research Exchange was established by the P.I. (Mark Gluck, Ph.D., of Rutgers) and our lead Palestinian collaborator, Adel Misk, M.D. (faculty, Al-Quds), along with Mohammad Herzallah, M.D. (a Palestinian medical doctor, now a doctoral candidate at Rutgers), and Yasin Tayem, M.D., Ph.D. (faculty, Al-Quds); for more information see http://neuroscience.med.alquds.edu and http://www.alquds.rutgers.edu. The current exchange program provides the framework within which the scientific, educational, and infrastructural programs proposed here will lead, ultimately, to the establishment of a future Palestinian Neurosciences Institute at Al-Quds University. With this R21 grant, the investigators will (1) further develop the environment, personnel, and infrastructure at Al-Quds University for neuroscience research, (2) study the cognitive correlates of Major Depressive Disorder among West Bank Palestinians, focusing on how the disease and antidepressant medications alter learning and decision making, and (3) use the collected data and expected infrastructural growth as the basis for a future R01 proposal to the NIH Brain Disorders in the Developing World program. Although the current research focus will be on MDD, the infrastructure created, and the Palestinian faculty and students to be trained, will likely expand to address many other mental health and brain research issues in coming years. This will create at Al-Quds University in Abu Dis, West Bank, a regional powerhouse in neuroscience, neurology, and psychiatry research and training. Based in the West Bank/Palestinian Territories, these new programs will be a formidable contributor to research and health care in the West Bank, as well as a viable research and educational partner for collaborative relationships worldwide and in the Middle East.